单项选择题

The United States is widely recognized to have a private economy because privately owned business play (1) roles. The American free enterprise system (2) private ownership more than public sectors. Private businesses produce (3) goods and services, (4) almost two-thirds of the nation’s total economic output goes to (5) for personal use. The consumer role is (6) great, in fact, that the nation is sometimes characterized as having a " (7) economy".
This emphasis (8) private ownership arises, (9) , from American beliefs about personal freedom. From the time the nation was (10) , Americans have (11) excessive government power, and they have sought to (12) government’s authority over individuals—including its role in the economic realm.
(13) Americans generally believe that an economy largely with private ownership is likely to operate more (14) than (15) with substantial government ownership. When economic forces are unfettered, Americans believe, supply and demand (16) the prices of goods and services. Prices, in tum, tell businesses what to produce; if people want more of particular goods than the economy is producing, the price of the goods (17) . That catches the attention of new or other companies that, (18) an opportunity to earn profits, start producing more (19) that goods. On the other hand, if people want less of the goods, prices fall and less competitive producers either go out of business or start producing (20) goods.

（8）（）